Despite the discovery of novel beta-lactamases such as extended-spectrum beta-lactamases (ESBLs), imported AmpC, and carbapenem-hydrolyzing beta-lactamases at least a decade ago, there remains a low level of awareness of their importance and how to detect them. There is a need to increase the levels of awareness of clinical laboratories about the detection of newer beta-lactamases. Therefore, a...

Aztreonam was investigated as to its characteristics as a substrate, inhibitor and inducer for the well-defined beta-lactamases of Gram-negative bacteria, and its antibacterial efficacy as to bacterial cells producing eight types of beta-lactamases was also evaluated. Aztreonam was hydrolyzed at measurable rates by class A beta-lactamases, a TEM-2 type penicillinase and the Proteus vulgaris cep...

Production of extended-spectrum beta-lactamases and plasmid-mediated AmpC enzymes was investigated among 291 Escherichia coli and 282 Klebsiella pneumoniae isolates that showed decreased susceptibilities to extended-spectrum cephalosporins from seven Taiwanese medical centers. CTX-M-type and SHV-type enzymes were the most prevalent extended-spectrum beta-lactamases. CMY-2-like and DHA-1-like be...

Antibiotic resistant ?-lactamases are diverse and complex enzymes produced by most of the Gram-negative bacteria that mediated number plasmids. The impact these has posed a major threat to health sectors challenged available treatment options for both community hospital acquired infections. These include uncomplicated severe life-threatening Moreover, with resistance cephalosporin drugs MDR str...

The properties and regulation of beta-lactamases produced by certain R factors derived from ampicillin-resistant strains of Escherichia coli and Klebsiella were characterized. beta-Lactamase activity was determined by the acidimetric method with phenol red as indicator. The sensitivity of this assay was increased by employing phosphate buffer at a final concentration of 0.4 mm; as little as 0.0...

Bacterial beta-lactamases are the major causes of resistance to beta-lactam antibiotics. Three classes of these enzymes are believed to have evolved from ancestral penicillin-binding proteins (PBPs), enzymes responsible for bacterial cell wall biosynthesis. Both beta-lactamases and PBPs are able to efficiently form acyl-enzyme species with beta-lactam antibiotics. In contrast to beta-lactamases...

background guiana extended-spectrum (ges-2) as one of the extended-spectrum β-lactamases (esbls), produced by pseudomonas aeruginosa, is able to compromise the effectiveness of imipenem and tends to be geographically limited. objectives the aim of this study was to detect the spread of ges-2 β-lactamase gene among esbl- producing p. aeruginosa isolates in a teaching hospital in kashan, iran. ma...

conclusions the present study showed that bla oxa-23-like was the most frequent carbapenemase identified among carbapenem-resistant a. baumannii isolated in tehran hospitals. evaluation of antibiotic resistance genes in a. baumannii, is necessary to control further dissemination of these antibiotic resistant genes. results results showed that 123 of 131 (93.89%) acinetobacter species, possessed...

Presence of extended spectrum beta-lactamases (ESBL) in bacteria is a growing health concern of global significance. The local, regional, national, and international epidemiological studies for extended spectrum beta-lactamases-producing Enterobacteriaceae and their encoding genes in foods are still incomplete. The objective of this study was to determine the occurrence of extended spectrum bet...